Marc Dreier admitted charges of conspiracy, money laundering, wire fraud and securities fraud in May after being arrested late last year in Toronto.
According to the US government, he began selling fake promissory notes issued by a New York-based real estate development company in 2004 and notes issued by Ontario Teachers' Pension Plan in Canada at the start of 2008.
The overall loss to investors and clients exceeded $400 million, the authorities stated.
"I am sorry, deeply sorry for the harm and sadness I have caused so many people," Dreier, 59, said, adding: "At this point, all I can do is express my shame and remorse."
Dreier formed his own law firm in 1996, which he had since expanded to offices in New York and Los Angeles.
In related news, New York prosecutors recently charged 25 people - including lawyers and bankers - with committing mortgage fraud.